Starting device



H. KLEIN ETAL STARTING DEVICE Filed Aug 2, 1940 June 3, 1 941.

Fig. 2.

Patented June 3, 1941 7 UNITED STATES PATENT! OFFICE; 2,244,627 I f STARTING DEVICE Hermann Klein, Vaihingen-Rohr, and Karl Bothn ermel, .Reichenbach-Fils, Germany, assignors to Robert Bosch G. 111. b. H., Stuttgart, Germany Application August. 2, 1940, Serial No. 349,552 In Germany July 8, 1939 Claims.

" This invention relates to a starting device for internal combustion engines of the typejin which a coupling member is engaged with the. engine by, means of ,a push rod operating in the axi'al direction of the coupling membnagainst action of a return spring.

It is an important object of the present invenbecome apparent from the withindisclosures, the

invention consists not only in. the structures herein pointed out and illustrated by the draw.-

-ings, but includes further structures coming within the scope of what. hereinafter claimed. v i

The character of the invention, however, may be bestunderstood by reference to certain of its structural forms, as illustrated bythe accompanyingdrawing in which:

Fig. lis a side elevation, partly in section of a starting device having the invention applied thereto. 0 r 7 ,Fig. 2 is a detail, partly in section.

Fig. 3 is a cross sectional view on line 3-3: of

may be Similar characters of reference denote similar parts inthe different views. n. 1 According to an important feature of the present invention a transmission member is arranged within the hollow driving shaft of the pinion,; between the pushrod andthencoupling member, consisting of relatively slidable parts which are lockedcby means of catch members that can be released bycentrifugal force'at. a predetermined seed.

Referring now to the drawing in greater detail, item a is a pinion constituting the coupling member of the starting device, by which the:

same can beconnected with a gear a of the engine. to a hollow shaft b which is seated in a bearing bracket o of the starting device and, at its end projecting into the starter casing 11, is connected, through a free motion friction clutch e, with a gear system (not shown) which in turn can be driven from any source of power" (not shown), such as an electric motoryfly wheel or the like.-

The clutch e and its drive may be of any conventional form and has no direct bearing upon the operating principle of the present invention, so that a more detailed 'description thereof will not be required; The hollow shaft together with parts of the friction clutch is arranged to be axially slidable in thebearlng, to permit the pinion to be thrown into meshwith a member,- such as the flywheelgear a, of the engine.

A push rod .f arranged co-axially with the hollow This pinion is connected, by a key a",

shaft and extending thi ough the starting device, with its] inner end projecting into the hollow shaft, serves for axially moving the hollow shaft with the pinion. Provided between the end of the push rod and thepinion isa transmission member g-by whichthe control motion of the rod fmay be transmittedto the hollow shaft and the pinion connected thereto.

The transmission member g is shown in greater detail in Figs. 2 and 3 and comprises two annular bodies h and i interconnectedby a sheet metal sleeve k. The opposite ends of a pressure spring in the sleeve bear against the annular body h and against a spring plate 11, respectively. A rod 0 riveted to the spring plate extends through the annular body 2 and has athickened end portion 0 projecting from the body 2', thus forming a shoulder p. A ball q is seated in a recess on the front end of the rod 0. The body 2' isformed with two segment-shaped. recesses r' for receptionof a pair of centrifugal weights sand t which are held together by a-helical spring a formed intoa ring which is seated in grooves 21 of the two 'centrifugal weights. The weights in their position of rest project inwardly into the bore of the annularfbody. Thecomplete transmissionmember g forming an" independent. selffull mesh with gear a, Assumingthatthe operover, a spring 1/ engaging at one end a shoulder b of the hollow shaft b, through a spring plate 2 and balls 2 and hearing at its opposite end against an annular groove 0 in the bearing bracket c, serves as a return spring. I

The operation of our novel device is as follows:

Inorder to start the engine, the operator or" driver moves the push rod f engaging the ball q of rod 0. The thrust motion is transmitted from the shoulder pof' the rod 0 to the centrifugal weights which at the beginning of the starting operation are in the position of rest, and withal the hollow shaft b and the. pinion a are axially moved, to thevleft, through the sleeve k, and against action of spring 2/, untilthepinion is'in ator, after the engine has been started and has picked upspeed, should fail to withdraw the push rod for demeshing thepinion, the centrifugal weights s and towing to the high speed imparted to them through the pinion and the transmission member g, will spread out so far as to clear the shoulder p and to permit their sliding. over the thickenedportion dot the rod 0. Thus, the

return spring 11 is permitted to withdraw the engage the thickened portion of the rod 0. When the driver withdraws the thrust rod f, the spring m acts to move the rod to the right, thus withdrawing the thickened portion 0' thereof from the space intermediate the two centrifugal weights s and t which in consequence thereof fall in behind the shoulder 11, whereby the starting device is made ready for another starting operation.

It will thus be seen from the foregoing that our novel starting device is foolproof inasmuch as automatic de-meshing of the pinion a from the engine gear a is ensured if the driver omits to uncouple the starting device in time.

The method and apparatus of the present invention have been described in detail with reference to specific embodiments. It is to 'be understood, however, that the invention isn'ot limited by such specific reference,but is broader in scope and capable of other embodiments than those specifically described and illustrated in the drawing. I e

It is also to be understood that the following i claims are intended to coverv all of thegeneric and specific features of theinvention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

We claim:

1. A starting device for internal combustion engines, comprising in combination a coupling member for transmitting the driving motion of the starter motor to the engine, a hollow driving shaft for said coupling member, a push-rod operating axially of said shaft and adapted to engage said coupling member with the engine, by axial displacement of said coupling member, a return spring for said coupling member, and a transmission member disposed within said driving shaft and establishing a thrust-transmitting connection between said coupling member and said push rod, said transmission member comprising a plurality .of parts which are axially slidable with respect to each other for permitting reduction of the distance between the thrusttransmitting end faces of the transmission member, under action of said return spring, and means adapted to lock saidslidable parts in their position of a maximum distance between said. faces and to release said parts by action of a predetermined centrifugal force, whereby said coupling member will be disengaged from the engine at a predetermined speed, under action of said return spring. I

2. A starting device for internal combustion engines, comprising in combination a coupling member for transmitting the driving motion of the starter motor to the engine, a hollow driving shaft for said coupling member, a push'rod operating axially of said shaft and adapted to engage said coupling member with the engine, by axial displacement of said coupling member, a return'spring for said coupling member, and a transmission member disposed within said driving shaft and establishing a thrust-transmitting connection between said coupling member and said push rod, said transmission member comprising a plurality of parts which are axially slidable withrespect to each other for permitting reductionof the distance between the thrusttransmitting end faces of the transmission memher, under action of said return spring, and means adapted to lock said slidable parts in their position of maximum distance between said faces and to release said parts by action of a predetermined centrifugal force, whereby said coupling member will be disengaged from the engine at a predetermined speed, under action of said return spring, said transmission member being in the form of an independent. self contained unit.

3. A starting device for internal combustion engines, comprising in combination a coupling member for transmitting the driving motion of the starter motor to the engine, a hollow driving shaftfor said coupling member, a push, rod operating axially of said shaft and adapted to engagesaid coupling member with the engine, by axial" displacement of said coupling member, a return spring for said coupling member, and. a transmission member disposed within said driving shaft and establishing. a thrust-transmitting connection between said coupling member and said push rod, said transmission member comprising a sleeve, two annularend members interconnected by said slee've,spring-loaded centrifugal weights fitting into segment-shaped recesses of one of said end members, a spring-loaded rod extending centrally between said centrifugal weights and adapted to transmit the axial thrust movement of said-push rod upon said transmission member, through said centrifugal weights,

by engagement of a shoulder of said spring-loaded rod with the inner portions of the side faces of said centrifugal weights, in the normal position of said weights, said centrifugal weights being adapted to clear said shoulder at a predetermined speed, for permitting disengagement of said coupling member under action of said return spring.

4. A' starting device for internal combustion engines comprising, in combination, a coupling member adapted to engage-and'drive a member of the engine, a hollow driven shaft within which said coupling member is mounted and which engages said coupling member, a return spring for said coupling member, a pushrod arranged in said shaft and adapted to axially displace said coupling member, andsa transmission member between said push rod and said coupling member, said transmissionmember comprising two spring-loaded partsaxially slidable with respect to each other, and'control members acted upon by centrifugal force and adapted to releasably lock said parts in their position of maximum distance apart.

5; A starting device for internal combustion engines comprising, in combination, a pinion adapted to engage and drive a member of the engine, resilient means normally holding said pinion out of engagement with said member, and

' manually operable means for moving said pinion HERMANN KLEIN; KARL ROTHERMEL. 

